CN112423587A

CN112423587A - Micelle delivery method

Info

Publication number: CN112423587A
Application number: CN201980040616.2A
Authority: CN
Inventors: R·米蒂加; W·安; J·罗维森; E·皮尚诺娃
Original assignee: Pennokem Co ltd
Current assignee: Evonik Operations GmbH
Priority date: 2018-06-19
Filing date: 2019-06-19
Publication date: 2021-02-26
Also published as: US20210253454A1; CA3103673A1; US20190380337A1; AU2019290649A1; IL279473A; MA52983A; MX2020013854A; WO2019246243A1; KR20210011496A; EP3809847A1; BR112020026199A2; PH12020552146A1; EP3809847A4

Abstract

Provided herein are compositions and methods for treating microbiologically contaminated water and microbiologically contaminated surfaces. The composition can comprise a micellar system comprising an equilibrium peroxycarboxylic acid solution and a surfactant.

Description

Micelle delivery method

Cross Reference to Related Applications

The present application claims priority from U.S. provisional application sequence No. 62/686,924, filed on 2018, 6/19/35/119 (e) (1), the contents of which are incorporated herein by reference.

Technical Field

The present invention relates to compositions and methods for treating microbiologically contaminated water and microbiologically contaminated surfaces.

Background

Microbial contamination of water in industrial applications can lead to the production of biofilms on industrial equipment. A typical biofilm is composed of a matrix of biopolymers embedded in bacteria. Biofilms can form on equipment used in many different industries where equipment surfaces are exposed to water contaminated with microorganisms, such as equipment used in oil and gas field operations or circulating cooling water systems. Biofilms can plug and corrode equipment, such as pipes and drilling machinery. This corrosion is commonly referred to as bio-corrosion or microbiologically influenced corrosion ("MIC"). Biofilms cannot be eliminated with standard antimicrobial agents. Standard agents may not be effective at penetrating the biofilm and are not always effective under field conditions including extreme temperatures and high salinity. Severe biofilm formation can require expensive and time consuming shut down operations for cleaning. The drilling equipment may need to be disassembled and cleaned at the surface. There is a continuing need for water treatment processes for industrial applications that effectively target the treatment of biofilms and any biofilm-forming microorganisms.

Disclosure of Invention

Provided herein are compositions and methods for treating microbiologically contaminated water and microbiologically contaminated surfaces. The composition can comprise a source of active oxygen, an organic acid, and a surfactant, wherein the organic acid and the source of active oxygen react to form an equilibrium peroxycarboxylic acid solution in a micellar system. The active oxygen source may be hydrogen peroxide, calcium peroxide, percarbonate, carbamide peroxide and mixtures thereof. In some embodiments, the active oxygen source may be hydrogen peroxide. In some embodiments, the organic acid may be acetic acid, formic acid, propionic acid, caprylic acid, and citric acid. The surfactant may be a nonionic surfactant, an anionic surfactant or a cationic surfactant. In some embodiments, the surfactant may be a linear alcohol or a derivative of a linear alcohol. The linear alcohol can be a C6-C12 linear alcohol. In some embodiments, the surfactant may be an alcohol ethoxylate, an alkoxylated linear alcohol, an ethoxylated castor oil, an alkoxylated fatty acid, an alkoxylated coconut oil, an alcohol sulfate, a monoglyceride phosphate, a diglyceride phosphate, or a combination thereof. The equilibrium peroxycarboxylic acid solution may include a peroxycarboxylic acid, an organic acid, and hydrogen peroxide. In some embodiments, the percarboxylic acid can be a C2-C12 percarboxylic acid. In some embodiments, the percarboxylic acid is peracetic acid.

Also provided are methods of making micellar systems comprising the equilibrium peroxycarboxylic acid solutions. The method may comprise the steps of: mixing about 30-50 wt% of an organic acid, about 10-20 wt% of a source of active oxygen, and about 1-15 wt% of a surfactant in an aqueous solution; and incubating the aqueous solution for a sufficient time to produce an equilibrium peroxycarboxylic acid solution.

Methods of reducing microbial contamination in aqueous fluids are also provided. The method may comprise the steps of: contacting the aqueous fluid with a composition comprising a micellar system that equilibrates the peroxycarboxylic acid solution and the surfactant for a time sufficient to reduce the level of microorganisms in the aqueous fluid. The aqueous fluid may be fresh water, pond water, seawater, brackish water, brine, oilfield fluids, produced water, tower water, or combinations thereof.

Methods of reducing microbial contamination in a subterranean environment including a wellbore are also provided. The method may comprise the steps of: introducing an aqueous composition comprising a micellar system comprising an equilibrium peroxycarboxylic acid solution and a surfactant into a wellbore; and contacting the well bore with the aqueous composition for a sufficient time to reduce microbial contamination. The microbial contamination may comprise free-floating microorganisms, sessile microorganisms or biofilms or combinations thereof. Methods of reducing microbial contamination of a surface are also provided. The method can include contacting the surface with an aqueous composition comprising a micellar system that equilibrates a peroxycarboxylic acid solution and a surfactant for a time sufficient to reduce microbial contamination. The microbial contamination may comprise a biofilm.

Methods of reducing microbial contamination of a surface are also provided. The method can include contacting the surface with an aqueous composition comprising a micellar system that equilibrates a peroxycarboxylic acid solution and a surfactant for a time sufficient to reduce microbial contamination. The microbial contamination may comprise a biofilm. The surface may comprise industrial equipment, medical equipment or equipment used in food preparation.

Drawings

These and other features and advantages of the present invention will be more fully disclosed in, or made apparent from, the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings, in which like numerals refer to like parts and further wherein:

FIG. 1a is a photograph of a biofilm on a control glass test strip after 72 hours of treatment with water. FIG. 1b is a photograph of a biofilm on a glass test strip after treatment with a PAA solution (PAA: hydrogen peroxide ratio 15.7: 10.4). FIG. 1c is a photograph of biofilm on glass test strips treated with composition 1 as shown in Table 8. FIG. 1d is a photograph of biofilm on glass test strips treated with composition 2 as shown in Table 8.

Detailed Description

The detailed description is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. The drawings are not necessarily to scale and certain features of the invention may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness. In the description, relative terms such as "horizontal," "vertical," "up," "down," "top" and "bottom" as well as derivatives thereof (e.g., "horizontally," "down," "up," etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description and are not generally intended to require a particular orientation. Terms including "inwardly" and "outwardly", "longitudinal" and "transverse" should be interpreted relative to each other or relative to an axis of elongation or rotation or center of rotation as appropriate. Terms concerning attachments, coupling and the like, such as "connected" and "interconnected," refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. The term "operatively connected" is such attachment, coupling or connection that allows the pertinent structures to operate as intended due to that relationship. The term "machine" shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. In the claims, means-plus-function clauses, if used, are intended to cover the structures described, suggested, or rendered obvious by the written description or drawings for performing the recited function, including not only structural equivalents but also equivalent structures.

The present invention relates to compositions and methods for treating microbiologically contaminated water and microbiologically contaminated surfaces. The inventors have found that a composition comprising a source of active oxygen, an organic acid and a surfactant produces an equilibrium percarboxylic acid solution in a micellar system. Surprisingly, the micellar system mitigates the decomposition of percarboxylic acids. The percarboxylic acids in the micellar system are stable over long periods of time even at elevated temperatures and in the presence of high concentrations of salts. Micellar systems provide an efficient delivery system for equilibrium percarboxylic acid solutions. Upon dilution, the activated percarboxylic acid is released from the micellar system. The composition exhibits biocidal activity against free-floating bacteria and biofilms. The composition also effectively dissolves tars, sludge and gelled polymers typically deposited on surfaces and equipment used in oil and gas wells. These stable compositions can be provided as one-component pre-mix formulations that can be added directly to an aqueous solution without the need to mix multiple reagents on site. These stable formulations can be effectively stored and transported.

We can refer to these compositions as either an equilibrated percarboxylic acid solution in a micellar system or a micellar equilibrated percarboxylic acid solution or a micellar delivery system. A percarboxylic acid solution, such as a peracetic acid solution, is typically a dynamic equilibrium mixture of water, acetic acid, hydrogen peroxide, and peracetic acid, as shown in equation 1 below:

the dynamic equilibrium between peracetic acid, acetic acid, hydrogen peroxide and water helps to maintain the stability of peracetic acid and the concentration of peracetic acid. One of ordinary skill in the art will recognize that in a dynamic equilibrium solution, the nominal measured concentration of the peracetic acid raw solution is the equilibrium concentration, and the actual measured concentration at any point in time will vary slightly.

The compositions disclosed herein are generally useful for treating water used in industrial applications, such as water flowing through pipes or other subterranean formations, for example in the energy industry, such as in oil and gas field operations, and in the paper or pulp industry. The compositions disclosed herein are also useful for cleaning and disinfecting surfaces or equipment in general, and equipment for oil and gas field operations in particular.

Without being bound by any particular theory, it appears that the surfactant stabilizes the percarboxylic acid by forming micelles. Micelles are spherical structures formed by the self-assembly of amphiphilic molecules (e.g., surfactants). Amphiphilic molecules have hydrophilic/polar regions, also known as "heads", and hydrophobic/non-polar regions, also known as "tails". Micelles are typically formed in aqueous solution such that the polar head region faces the outer surface of the micelle and the non-polar tail region faces the inner surface to form the core. When the Critical Micelle Concentration (CMC) is reached, micelles are typically formed by the surfactant. CMC is the concentration of surfactant below which the surfactant is monomeric in solution, and above which all other surfactants form micelles. Micelles are generally spherical and their size depends on the composition, ranging from about 2 to 900 nm. With respect to the compositions disclosed herein, the polar group of the surfactant forms a strong bond with the peroxycarboxylic acid as it is produced. The micelles appear to surround and stabilize the peroxycarboxylic acid, thereby mitigating the decomposition of peroxycarboxylic acid that normally occurs in aqueous solutions. When the micellar solution is added to the aqueous solution to be treated, the micellar solution is diluted below the CMC concentration of the surfactant, the micelles are broken and the peroxycarboxylic acid is released.

The compositions disclosed herein include a source of active oxygen. We may also refer to the active oxygen source as a source of peroxygen. The active oxygen source may be hydrogen peroxide, calcium peroxide, carbamide peroxide, or percarbonate, or a combination of one or more of hydrogen peroxide, calcium peroxide, carbamide peroxide, perborate, or percarbonate. The percarbonate may be sodium percarbonate, sodium percarbonate peroxide, sodium peroxydicarbonate, potassium percarbonate, potassium peroxycarbonate or potassium peroxydicarbonate. In some embodiments, the composition may include or exclude hydrogen peroxide, calcium peroxide, carbamide peroxide, or percarbonate, or a combination of one or more of hydrogen peroxide, calcium peroxide, carbamide peroxide, perborate, or percarbonate.

The concentration of the active oxygen source may vary. The concentration of the active oxygen source may range from about 8 wt% to about 25 wt%. Thus, the active oxygen source concentration may be about 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt%, 10 wt%, 10.5 wt%, 11 wt%, 11.5 wt%, 12 wt%, 12.5 wt%, 13 wt%, 13.5 wt%, 14 wt%, 14.5 wt%, 15 wt%, 15.5 wt%, 16 wt%, 16.5 wt%, 17 wt%, 17.5 wt%, 18 wt%, 18.5 wt%, 19 wt%, 19.5 wt%, 20 wt%, 20.5 wt%, 21 wt%, 21.5 wt%, 22 wt%, 22.5 wt%, 23 wt%, 23.5 wt%, 24 wt%, 24.5 wt%, or 25 wt%.

The compositions disclosed herein also include an organic acid. Exemplary organic acids may include, but are not limited to, acetic acid, citric acid, formic acid, propionic acid, isocitric acid, aconitic acid, and propane-1, 2, 3-tricarboxylic acid, lactic acid, benzoic acid, salicylic acid, glycolic acid, oxalic acid, sorbic acid, malic acid, maleic acid, tartaric acid, caprylic acid, ascorbic acid, or fumaric acid. In some embodiments, the composition may include or exclude acetic acid, citric acid, formic acid, propionic acid, isocitric acid, aconitic acid, and propane-1, 2, 3-tricarboxylic acid, lactic acid, benzoic acid, salicylic acid, glycolic acid, oxalic acid, sorbic acid, malic acid, maleic acid, tartaric acid, caprylic acid, ascorbic acid, or fumaric acid.

The concentration of the organic acid may vary. The concentration of the organic acid may be about 20 wt% to about 60 wt%. Thus, the organic acid concentration may be about 20, 22, 25, 30, 35, 36, 37, 38, 40, 42, 45, 46, 47, 48, 49, 50, 55, or 60 weight percent.

The compositions disclosed herein also include a surfactant. The surfactant may be a linear alcohol or a derivative of a linear alcohol. In some embodiments, the linear alcohol or derivative of a linear alcohol may be a C6-C15 linear alcohol. The derivative of a linear alcohol may be a linear alcohol in which an-OH group on the linear alcohol is alkoxylated. In some embodiments, the-OH group may be ethoxylated, for example ethers, such as ethoxylated or alkoxylated alcohols containing an ether group C-O-C. The degree of ethoxylation may vary. The ethoxylated linear alcohols may include, for example, 1,2,3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or more ethylene oxide units. Such ethoxylated linear alcohols are typically nonionic surfactants. In some embodiments, the-OH group may be propoxylated.

In some embodiments, the derivative of the linear alcohol may be an ester, for example a sulphate ester, such as Sodium Dodecyl Sulphate (SDS), or a phosphate ester, for example phosphorylated monoglycerides and diglycerides (PDMG). These surfactants are typically esters of alcohols and mineral acids. Such esters are typically anionic surfactants.

Useful surfactants are chemically stable surfactants that are compatible with the oxidizing agents disclosed herein and do not promote phase separation, curing, or gas evolution when combined with the oxidizing agents. Useful surfactants are also compatible with oilfield fluid components such as clay stabilizers, corrosion inhibitors, and friction reducers. Such surfactants are effective emulsifiers, i.e. lead to the production of stable micelles. Useful surfactants are resistant to divalent cations typically present in aqueous solutions such as reservoir brines. Such useful surfactants are also stable at temperatures up to about 120 ℃ and will also be effective in subterranean wells that can reach temperatures up to about 95 ℃. Useful characteristics of surfactants also include effective cleaning performance, rinsing characteristics, wetting ability, and biodegradability, such as those that can be found in plant-based biodegradable surfactants.

The surfactant may be a nonionic surfactant, an anionic surfactant or a cationic surfactant. The surfactant may or may not include a nonionic surfactant, an anionic surfactant, or a cationic surfactant. Exemplary nonionic surfactants include, but are not limited to, alcohol ethoxylates, alkoxylated linear alcohols, ethoxylated castor oils, alkoxylated fatty acids, and alkoxylated coconut oils. The nonionic surfactant may be a biodegradable synthetic or plant-based surfactant.

Anionic surfactants may include, for example, alcohol sulfates, such as Sodium Dodecyl Sulfate (SDS). SDS is typically made from inexpensive coconut oil and palm oil. Other useful anionic surfactants include sodium salts of mono-and diglycerides of phosphoric acid. Exemplary sodium salts of mono-and diglycerides of phosphoric acid include food grade phosphate esters derived from vegetable oils.

The surfactant may be, for example, an ethoxylated linear alcohol, such as C9 to C15 alcohol and an average mole number of ethoxylations of 6 to 8 (R (OC)₂H₄)_nOH, where R may vary and the number n may vary, ethoxylated castor oil, ethoxylated fatty acids, alkoxylated alcohol sulfonates, linear alkyl sulfates. Exemplary surfactants include Alcohol Ethoxylates (AE), Alkoxylated Linear Alcohols (ALA); mono-and diglycerides of phosphoric acid; ethoxylated Alcohols (EA); disodium Lauryl Sulfosuccinate (DLS); sodium Dodecyl Sulfate (SDS); diphenyloxide disulfonate (DOD); and Dodecyl Diphenyl Oxide Disulfonate (DDOD).

The surfactant may be a single surfactant or a mixture of two, three, four, five, six or more different surfactants. For example, the surfactant may be a mixture of an Alcohol Ethoxylate (AE) and an Alkoxylated Linear Alcohol (ALA).

The concentration of the surfactant may vary. The concentration of the surfactant may be from about 0.5% to about 20% by weight. Thus, the surfactant concentration may be about 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18.5, 19, 19.5, or 20 weight percent. Regardless of the concentration, the amount of surfactant should be sufficient to promote micelle formation, that is, it should be present in an amount above the critical micelle concentration and sufficient to stabilize the percarboxylic acid.

In some embodiments, the composition may or may not include a stabilizer, for example, to stabilize surfactant emulsions, to further stabilize peroxyacids, to chelate metal ions, and to inhibit precipitation. The stabilizer may be a hydroxy acid. Exemplary hydroxy acids include, but are not limited to, citric acid, isocitric acid, lactic acid, gluconic acid, and malic acid. The stabilizer may be a metal chelating agent, such as ethylenediaminetetraacetic acid (EDTA). Metal chelators may be used in oilfield produced water to keep metal ions in solution that would otherwise interfere with the function of the surfactant.

The concentration of the stabilizer may vary. The concentration of the stabilizer may be about 0.1 wt% to about 5 wt%. Thus, the stabilizer concentration may be about 0.1 wt%, 0.2 wt%, 0.5 wt%, 0.7 wt%, 0.8 wt%, 1.0 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.7 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt%, or 5.0 wt%.

Provided herein are methods of making micellar delivery systems. The active oxygen source, organic acid and surfactant may be prepared as an aqueous stock solution and diluted for use. The source of active oxygen, the organic acid, and the surfactant may be mixed in an aqueous solution. The source of active oxygen, the organic acid and the surfactant may be mixed simultaneously, substantially simultaneously or sequentially. For example, the active oxygen source, organic acid, and surfactant may be mixed over a period of about 15 seconds, 20 seconds, 30 seconds, 40 seconds, 50 seconds, 60 seconds, 90 seconds, 120 seconds, 150 seconds, 3 minutes, 3.5 minutes, 4 minutes, 4.5 minutes, 5.0 minutes, 5.5 minutes, 6.0 minutes, 6.5 minutes, 7.0 minutes, 7.5 minutes, 8.0 minutes, 8.5 minutes, 9.0 minutes, 9.5 minutes, 10 minutes, 12 minutes, 15 minutes, 18 minutes, 20 minutes, 25 minutes, or 30 minutes. In some embodiments, the organic acid may be diluted into water, and then the surfactant added. The source of active oxygen may then be added to the mixture of organic acid and surfactant. In some embodiments, once the organic acid and surfactant have been mixed, for example within a few minutes, a source of active oxygen may be added to the mixture of organic acid and surfactant. In some embodiments, the mixture of organic acid and surfactant may be stored and then the active oxygen source may be added at a later time. In some embodiments, the components may be mixed, for example, by stirring or gentle agitation.

The source of active oxygen, the organic acid, and the surfactant may be mixed in any order. In some embodiments, the active oxygen source may be added after the mixing of the organic acid and the surfactant. The aqueous solution may be incubated to produce an equilibrium percarboxylic acid solution in the micellar system. The formation of percarboxylic acid can be monitored over a period of hours, days or weeks by auto-titration or other methods (e.g., spectrophotometry, wet titration test kit or HPLC) to determine if equilibrium has been reached. The time to reach equilibrium may vary based on a number of factors including, for example, the organic acid concentration, the active oxygen source concentration, the particular surfactant, the temperature, the presence of additives (e.g., sulfuric acid catalyst). The time to reach equilibrium may be, for example, about 8 days to about 50 days, such as about 8 days, 10 days, 12 days, 14 days, 18 days, 20 days, 21 days, 24 days, 28 days, 30 days, 35 days, 40 days, 45 days, or 50 days. Typically, an equilibrium solution is one in which the measured concentration of percarboxylic acid does not vary by more than about 1% over a period of about seven days.

Depending on the structure of the organic acid, a variety of different percarboxylic acids can be produced in micellar systems. The percarboxylic acids produced may have, for example, 2 to 12 carbon atoms. Percarboxylic acids may include organic aliphatic peracids having 2 or 3 carbon atoms, such as peracetic acid and peroxypropionic acid. Other peracids can be formed from organic aliphatic monocarboxylic acids having 4 or more carbon atoms, such as acetic acid (acetic acid), propionic acid, butyric acid (butyric acid), isobutyric acid (2-methyl-propionic acid), valeric acid, 2-methyl-butyric acid, isovaleric acid (3-methyl-butyric acid), 2-dimethyl-propionic acid, hexanoic acid, heptanoic acid, and octanoic acid. Other percarboxylic acids can be formed from organic dicarboxylic and tricarboxylic acids, such as citric, oxalic, malonic and glutaric, succinic, malic, glycolic and adipic acids.

Typically, an equilibrium percarboxylic acid solution is a solution in which the concentration of percarboxylic acid (e.g., peracetic acid) remains stable over time. Typical equilibrium percarboxylic acid solutions vary by about 1% or less from the target concentration.

The equilibrium concentration of the percarboxylic acid may vary depending on the particular source of active oxygen, organic acid, and surfactant. Generally, useful equilibrium concentrations will be about 8-20% by weight of the total composition. Thus, the equilibrium concentration of the produced percarboxylic acid (e.g., peracetic acid) can be about 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt%, 10 wt%, 10.5 wt%, 11 wt%, 11.5 wt%, 12 wt%, 12.5 wt%, 13 wt%, 13.5 wt%, 14 wt%, 14.5 wt%, 15 wt%, 15.5 wt%, 16 wt%, 16.5 wt%, 17 wt%, 17.5 wt%, 18 wt%, 18.5 wt%, 19 wt%, 19.5 wt%, or 20 wt%.

After storage at room temperature (about 22 ℃) for at least about 150 days, the equilibrated percarboxylic acid solution in the micellar system disclosed herein will typically retain about 80% of the initial percarboxylic acid activity (also known as active oxygen) determined when equilibrium is reached. In some embodiments, the equilibrated percarboxylic acid solution in the micellar system disclosed herein will typically retain about 75%, about 70%, about 65%, about 60%, about 55%, or about 50% of the initial percarboxylic acid activity, as determined when equilibrium is reached after storage for at least one hundred and fifty days.

The pH of the equilibrated percarboxylic acid solution in the micellar system is generally in the acid range. The pH may range from about less than 1 to less than 4. The pH may be about pH 0.5, about pH 0.8, about pH 1.0, about pH 1.1, about pH 1.2, about pH 1.5, about pH 1.7, about pH 2.0, about pH 2.2, about pH 2.5, about pH 2.7, about pH 3.0, about pH 3.2, about pH 3.5, about pH 3.7, or about pH 4.0.

The compositions disclosed herein are generally useful for treating water contaminated with microorganisms, or water at risk or suspected of being contaminated with microorganisms. The compositions may also be used in equipment, such as pipelines, drilling equipment, storage tanks, or other industrial equipment, that has been in contact with, or is at risk of or suspected of having been contaminated with microorganisms. The composition can also be used to treat equipment contaminated with biofilm. In some embodiments, the composition can be used to treat a medical device. In some embodiments, the compositions can be used to treat equipment and surfaces used in food preparation.

The water may be produced water from oil and gas field operations, industrial wastewater, municipal wastewater, process water, mixed sewer overflow, rainwater, flood water, storm run off water, or drinking water. The water may be fresh water, pond water, brackish water, seawater or brine.

The methods disclosed herein are particularly useful for treating produced water produced from oil and gas production. Such produced water may not be suitable for treatment in municipal wastewater treatment facilities, which are typically pumped into previously produced subsurface injection wells. Microbial contamination of such water can result in the formation of biofilms on drilling and pumping equipment. Typical well pump formulations may include biocides, friction reducers, surfactants, clay stabilizers, and corrosion inhibitors, which are mixed together in situ and pumped down the well. Such components may be incompatible, particularly when in contact with high salinity brines found in oil fields. Methods to overcome this incompatibility may include diluting the components and extending the amount and time of treatment. However, these methods may result in higher costs and are not always effective in removing microbial contamination and biofilm. The compositions disclosed herein can be used to treat process water to treat existing biofilms, reduce the potential for new biofilm formation, and dissolve sludge or tar build-up on pipelines and drilling equipment. These compositions may also be added to fracturing fluids to reduce microbial contamination.

The composition is compatible with high salinity conditions, such as water containing 0.5%, 1.0%, 2.0%, 3.0%, 4.0%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 30%, 35% or more dissolved salts. The compositions are also useful and stable at higher temperatures, for example, temperatures greater than 30 ℃, 35 ℃, 40 ℃, 50 ℃, 55 ℃, 60 ℃ or higher.

The composition may be added to the water to be treated in an amount sufficient to provide from about 1ppm to about 1000ppm of the activated percarboxylic acid in the water to be treated. Thus, for example, the equilibrium percarboxylic acid solution in the micellar system can be added to the water to be treated or to the water for plant treatment at a concentration of about 1ppm, about 2ppm, about 5ppm, about 10ppm, about 15ppm, about 20ppm, about 25ppm, about 30ppm, about 35ppm, about 40ppm, about 45ppm, about 50ppm, about 55ppm, about 60ppm, about 65ppm, about 70ppm, about 75ppm, about 80ppm, about 85ppm, about 90ppm, about 95ppm, about 100ppm, about 120ppm, about 150ppm, about 180ppm, about 200ppm, about 300ppm, about 400ppm, about 500ppm, about 600ppm, about 700ppm, about 800ppm, about 900ppm, or about 1000ppm of the active percarboxylic acid. In some embodiments, the concentration of the equilibrium percarboxylic acid solution in the water to be treated may be from about 50 to about 100 ppm. In some embodiments, the concentration of the equilibrated percarboxylic acid solution in the micellar system may be about 58ppm, about 59ppm, about 63ppm, about 66ppm, about 67ppm, or about 68 ppm.

In some embodiments, the composition may be added to the water to be treated at a level of, for example, about 50ppm to about 8000ppm, based on the weight of the micelle composition.

The duration of the treatment may vary. Generally, a useful treatment will result in a reduction of viable microorganisms in the treated water. With respect to biofilm, the effectiveness of a treatment can be determined by the extent to which biofilm is reduced on the contaminated surface. The duration of the treatment may be from about 30 minutes to 24 hours or more. Exemplary treatment times may be about 30 minutes, about one hour, about two hours, about four hours, about six hours, about eight hours, about 10 hours, about 12 hours, about 15 hours, about 18 hours, about 20 hours, or about 24 hours.

Generally, the reduction in microbial contamination can be determined by determining the level of viable microorganisms in the water. In some embodiments, the reduction in microbial contamination may be about 50%, about 80%, about 90%, about 95%, about 99%, or about 99.9% reduction in contamination of the treated water compared to the level in the water prior to treatment or compared to a reference level. Alternatively or additionally, the reduction amount may be designated as a Log10 reduction amount. Thus, in some embodiments, the reduction in microbial contamination may be a reduction of 1,2,3, 4, 5, 6, or 7Log relative to an untreated control sample. The level of microbial contamination can be determined, for example, by standard culture methods, nucleic acid amplification techniques (e.g., polymerase chain reaction) and immunoassays involving microbial growth.

The compositions disclosed herein are also useful for cleaning and disinfecting surfaces or equipment in general, and equipment for oil and gas field operations in particular. Such surfaces are often covered with deposits of sludge, tar, inorganic scale, gelled friction reducers, polymers and partially hydrolyzed polyacrylamides or other by-products of drilling wells, which are difficult to remove in subterranean environments.

The compositions and methods disclosed herein are useful for treating water and equipment exposed to a variety of microbial contaminants, including, for example, bacteria, viruses, fungi, protozoa, and algae. The composition can be applied to planktonic and sessile forms of bacteria, viruses, fungi, protozoa and algae. The compositions are useful for aerobic and anaerobic microorganisms, for example, gram positive bacteria, such as Staphylococcus aureus (Staphylococcus aureus), Bacillus such as Bacillus subtilis (sp.), clostridium sp.); gram-negative bacteria, such as Escherichia coli (Escherichia coli), Pseudomonas sp (Pseudomonas sp) such as Pseudomonas aeruginosa and Pseudomonas fluorescens, Klebsiella pneumoniae (Klebsiella pneumoniae), Legionella pneumophila (Legionella pneumophila), Enterobacter sp (Enterobacter aerogenes) such as Enterobacter aerogenes, Vibrio sarenii (Serratia sp) such as Serratia marcescens (Serratia marcescens), Vibrio desulfaliens (Desulforus desulfurization) such as Vibrio desulforicola, and Vibrio desulfaligenes such as Desulfoenus desulforicus (Desulfoenus), Vibrio thioformis such as Desulfoenus fus (Desulfoenus), and Vibrio desulfaligenes such as Desulfoenus fumago (Desulfoenus fumonis); yeasts, for example Saccharomyces cerevisiae (Saccharomyces cerevisiae), Candida albicans (Candida albicans); molds such as Cephalosporium acremonium (Cephalosporium acremonium), Penicillium (Penicillium notatum), Aureobasidium pullulans (Aureobasidium pullulans); filamentous fungi, such as Aspergillus niger (Aspergillus niger), Cladosporium resinatum (Cladosporium resinae); algae, such as Chlorella (Chlorella vulgaris), Euglena (Euglena gracilis), Hitacea (Selenastrum capricanum); and other similar microorganisms such as phytoplankton and protozoa; viruses, such as hepatitis viruses and enteroviruses, e.g., poliovirus, echovirus, coxsackievirus, norovirus, SARS and JC virus. The compositions may also be used to treat water and surfaces exposed to bacterial spores (e.g., spores produced by clostridium).

Sulfur or sulfate reducing bacteria are a problem in subterranean wells, such as vibrio desulfovibrio and enterobacter desulfatous, which convert sulfur or sulfate present in such environments into sulfides, particularly hydrogen sulfide. These species can cause deterioration of the gas and oil products recovered from the subterranean formation. This deterioration of the natural gas and oil reduces the quality of the recovered product. Sulfide removal by chemical treatment of petroleum products is often required in downstream surface treatment processes. Sulfur or sulfate reducing bacteria, such as Vibrio and Enterobacter desulfulans, are difficult to treat with biocides. Sulfate-reducing bacteria are generally sessile bacteria, i.e., they adhere to a solid surface rather than floating freely in an aqueous fluid. Furthermore, sulfate-reducing bacteria are usually associated with slime-forming bacteria and are present in a film consisting of a matrix of biopolymers embedded in the bacteria. The interior of these biofilms is anaerobic and, even if the surrounding environment is aerobic, is very conducive to the growth of sulfate-reducing bacteria.

Examples

Example 1: materials and methods

The surfactant-peroxyacid solution was prepared by mixing together the organic acid, hydrogen peroxide (50% solution, from peroxichem LLC), surfactant and optional stabilizer, and dissolving the appropriate weight of each component in Deionized (DI) water to the desired concentration. The solution was kept at room temperature and the concentration of the components was measured periodically using an auto-titrator and standard titration methods. Typical concentrations of the components are shown in table 1.

TABLE 1 compositions for surfactant-peroxyacid solutions

The following surfactants were analyzed: alcohol Ethoxylate (AE) (Lumulse)^TMEST-916 from Vantage Specialties 100% active); alkoxylated Linear Alcohols (ALA) (Lumulse)^TMEST-500 from Vantage Specialties 100% active); phosphoric acid mono-and diglycerides (PMDG) (Lamchem)^TMPE 130K from Vantage Specialties 100% activity); sodium Lauroyl Glutamate (SLG) (Amisoft)^TMLS-11 from Ajinomoto Co, 100% active); ethoxylated Alcohol (EA) (A)

N91-8 from Stepan Co, 99% active); disodium Lauryl Sulfosuccinate (DLS) ((DLS))

Mate LA-40 from colonal Chemical, 40% activity); sodium Dodecyl Sulfate (SDS), from Sigma-Aldrich, 98% activity; diphenyl ether disulfonate(DOD)(

3B2 from Dow Chemical co., 45% activity); dodecyl Diphenyl Oxide Disulfonate (DDOD) ()

DB-45 from Pilot Chemical Co., 45% Activity).

Example 2

Glacial acetic acid, hydrogen peroxide, and a surfactant are dissolved in deionized water at room temperature, thereby preparing a solution containing a source of Active Oxygen (AO) and a surfactant. The surfactant was Sodium Lauroyl Glutamate (SLG) at a concentration of 1.0 wt%. Initial levels of peracetic acid (PAA), hydrogen peroxide, and active oxygen were analyzed as described in example 1. The solution was then stored at 22 ℃. The levels of peracetic acid (PAA), hydrogen peroxide, and active oxygen were analyzed at intervals. The concentrations of the components are shown in table 2.

TABLE 2 kinetics of peracetic acid formation in the presence of surfactants

As shown in table 2, acetic acid reacts with hydrogen peroxide in the presence of a surfactant to produce peracetic acid. Equilibrium levels of peracetic acid were reached after several weeks of culture. The total available active oxygen concentration in the system was relatively stable throughout the experiment. The total available active oxygen ("AO"), i.e., the sum of active oxygen in the total number of peroxide containing moieties, is calculated according to the following formula: AO ═ ΣⁿWhere n is the active oxygen amount of each compound in solution. The percentage of active oxygen for a given compound can be measured by MW O₂the/MW compound x 100% was determined. Peracetic acid contains 16/76 × 100%, i.e., 21%, active oxygen. Hydrogen peroxide contains 16/34 x 100%, i.e. 47% active oxygen. Thus, the total amount of AO can be calculated as: [ Peracetic acid weight%]X 0.21+ [ hydrogen peroxide weight%]X 0.47. As shown in table 2, the equilibrium peracetic acid concentration reached 15% at 41 days.

The solution was clear and homogeneous at the initial preparation and remained constant throughout the experiment.

Example 3

Solutions containing a source of Active Oxygen (AO) and various surfactants were prepared as described in example 1. Initial levels of peracetic acid (PAA) and hydrogen peroxide were analyzed as described in example 1. Initial measurements of peracetic acid and hydrogen peroxide are typically made after about 15 days of equilibrium has been reached (see column entitled "initial" in table 3). The solution was then stored at 22 ℃. The levels of peracetic acid and hydrogen peroxide were determined at the time points shown in table 3 below.

As shown in table 3, the ability of different surfactants to maintain peracetic acid stability varied. The effect of the various surfactants was also assessed by visual inspection. The solution was considered stable when no phase separation, solidification or gas evolution was observed. As shown in table 3, certain surfactants are physically incompatible with the starting materials and cause phase separation or solidification of the solution. Those combinations that exhibited stability and compatibility were selected for further analysis.

TABLE 3 stability of percarboxylic acid surfactant compositions

Example 4

Solutions containing a source of Active Oxygen (AO) and various additional surfactants were prepared as described in example 3. Determination of the initial concentration of Active Oxygen (AO) in solution⁰) And then stored at 22 ℃. The composition is periodically titrated and the concentration of Active Oxygen (AO) is determined. By AO/AO⁰The ratio of (A) to (B) in which AO is present to evaluate the relative stability of the solution⁰Is the initial active oxygen content.

As shown in table 4, the selected surfactants resulted in sustained peracetic acid stability.

TABLE 4 PAA-surfactant composition stability at 22 deg.C

Surface active agent	Concentration of%	Days at 22 ℃	AO/AO⁰	Appearance of the product
					AE	5	122	0.95	Homogenizing
AE	10	122	0.89	Homogenizing
					PMDG	5	122	0.90	Homogenizing
PMDG	10	122	0.81	Homogenizing
					EA	5	163	0.88	Homogenizing
EA	10	163	0.81	Homogenizing

Example 5

The dispersion state of the PAA-surfactant solution was analyzed. Typically, individual suspended particles in a colloidal solution scatter and reflect light (also known as the "tyndall effect"), while true solutions without suspended particles do not produce light scattering. The flask containing the aqueous solution of example 3 was irradiated with laser light emitted from the laser pointer. The laser light passes through the aqueous solution and essentially no "light path" appears, indicating that the "tyndall effect" in the solution is very weak. As a control, a commercial microemulsion was also irradiated with laser light and a "light path" appeared, consistent with the "tyndall effect" expected for the microemulsion. These results show that the PAA-surfactant system prepared in example 3 is relatively uniform in dispersion state in aqueous solution. These results also indicate that surfactant micelles are smaller than 40 to 900nm micelles in the commercial microemulsion control that produces the tyndall effect. These results further indicate that PAA-surfactant systems produce ultra-fine or nano-sized micelles.

Example 6

We evaluated the effect of temperature on the stability of PAA-surfactant solutions. An equilibrium PAA solution in a micellar system comprising 12.5 wt% peracetic acid, 9.4% hydrogen peroxide, and 4.5% surfactant Alcohol Ethoxylate (AE) was prepared as described in example 3. The solution was also stabilized by adding sulfuric acid (0.33%), citric acid (0.50%) and methylenephosphonic acid (Dequest, 0.83%). Aliquots of the equilibrated peracetic acid surfactant composition were incubated at 35 deg.C, 45 deg.C, or 55 deg.C.

The solution was titrated at intervals and the concentration of Active Oxygen (AO) was determined. By AO/AO⁰The ratio of (A) to (B) in which AO is present to evaluate the relative stability of the solution⁰Is the initial active oxygen content.

The results are shown in Table 5. These results indicate that the PAA-AE solutions are relatively stable. In addition, no phase separation or precipitation was observed in any of the solutions.

TABLE 5 PAA-surfactant composition stability at 35-55 deg.C

Temperature, C	Number of days	AO/AO⁰
			35	8	1.00
35	21	0.97
			35	35	0.95
45	8	0.93
			45	21	0.84
45	35	0.76
			55	8	0.86
55	21	0.70
			55	35	0.58

Example 7

We evaluated the effect of balancing the PAA-solution in a micellar system under simulated oilfield conditions. A solution containing 9.5% PAA and 4.5% surfactant alkoxylated linear alcohol ALA was prepared as described in example 3. The test liquid is

The Plus is from Halliburton, an aqueous solution of high molecular weight partially Hydrolyzed Polyacrylamide (HPAM). This liquid was added to tap water to a final concentration of 1.25%. Additionally, KCl was added to the solution in an amount of 1 wt% to simulate typical slickwater used in oil fields. The simulated oilfield composition was then treated with 1000ppm of a PAA-ALA solution.

The viscosity of the gel was measured using a standard bob R1, using a Viscometer Grace M3500 at 60-300 rpm. The measurements were carried out at 22 ℃ and 45 ℃.

The analysis results are shown in table 6. Each data point is the average of three experimental results.

TABLE 6 viscosity, cps at 22 ℃ of 1.25% HPAM

As shown in table 6, the viscosity of the HPAM solution at 22 ℃ decreased by about 22-26% depending on the rotational speed after treatment with the PAA-ALA composition. After treatment, the viscosity of the HPAM solution at 45 ℃ was reduced by about 42-46%. The viscosity of the treated and control test liquids was re-measured after 72 hours. The viscosity did not change practically any further.

Example 8

We evaluated the effect of an equilibrium PAA solution in a micellar system on the surface tension in a saline solution. Dissolving inorganic chloride in deionized water to final concentration of 8% NaCl, 1% KCl and 1% CaCl₂Thereby producing high salinity brine typical of oilfield conditions. A solution containing 12.5% by weight peracetic acid and 4.5% surfactant Alcohol Ethoxylate (AE) was prepared as described in example 3. The PAA-AE solutions were added to the saline solution at different concentrations (300ppm, 600ppm, and 1200 ppm).

The surface tension was determined using a Traube Stalagmometer at 22 ℃. The results are shown in Table 7. Each data point is the average of 12 measurements.

TABLE 7 surface tension of high salinity brine at 22 deg.C

Composition in ppm	Surface tension, mN/m
		0	80.7
300	47.9
		600	42.2
1200	38.6

As shown in table 7, treatment of saline with an equilibrium PAA solution in a micellar system results in a dose-dependent reduction in surface tension. These data indicate that the composition can effectively deliver balanced PAA to hydrophobic surfaces, such as those in oil and gas well walls.

Example 9

We evaluated the biocidal activity of PAA-surfactant solutions on microbial membranes using a CDC biofilm reactor from BioSurface Technologies. The reactor provides a continuous flow of nutrient broth through the vessel, which exposes the bacteria growing on the glass coupons to shear forces. The device simulates at least two typical features in oilfield operations: renewable nutrient sources and shear forces exerted on the biofilm. All reactor parts were cleaned with 1% Neutrad laboratory soap solution and rinsed thoroughly with deionized water, then dried, and then autoclaved in a 20 minute gravity cycle.

Pseudomonas aeruginosa (ATCC 15442) biofilms were grown in biofilm reactors on glass coupons at 25 ℃ for 48 hours. A solution containing 300mg/L sterile Tryptic Soy Broth (TSB) was used as the nutrient feed. 1mL of the working inoculum Pseudomonas aeruginosa was added through the inoculum. The first step is a 24 hour batch phase followed by a 24 hour continuous flow mode, at which time 100mg/L of the TSB solution is pumped into the stirred reactor at room temperature for about 24 hours to form a mature biofilm on the surface of the coupon.

After the biofilm growth phase was complete, the coupons were removed and rinsed by immersion in 30mL of dilution buffer. The test piece was placed into a sterile centrifuge tube and 4mL of biocide or buffer was added. The tube was then vortexed at a low speed to ensure complete strip coverage. At the appropriate time, the biocide was poured out and retained for chemical analysis of PAA and hydrogen peroxide. Then, 10mL aliquots of chemically neutralized agar broth with 0.5% sodium thiosulfate were added to each tube. One treated coupon was removed from each treatment group at the last time point for visual analysis.

Three solutions were used as biocides: PAA without surfactant; and 11.1%/4.2% PAA/hydrogen peroxide and surfactant Alcohol Ethoxylate (AE) and alkoxylated linear alcohol ALA ("composition 1"); and 12.6%/9.1% PAA/hydrogen peroxide and surfactant Alcohol Ethoxylate (AE) and alkoxylated linear alcohol ALA ("composition 2"); the composition of the biocides is shown in table 8.

TABLE 8 Biocide compositions

These compositions were diluted with deionized water prior to use to give an initial concentration of PAA surfactant active of 100 ppm. .

To recover residual viable bacteria from the test strip, the tube with the test strip was vortexed at the highest setting for 30s, and then sonicated at 45kHz for 30 s. This process was then repeated twice. Thereafter, the broth was serially diluted into Butterfield buffer and the dilution was plated at 3M^TM Petrifilm^TMOn an aerobic counting plate. The plates were incubated at 35 ℃ for 48 hours and then counted. Calculations were performed to obtain the Log of the solution at each time point₁₀ CFU/mL。

During the test, concentrations of PAA and hydrogen peroxide were monitored using Chemmetrics test kits K-7913F and K-5543. The results of this experiment are shown in table 9.

TABLE 9 mean Log₁₀Reduction and oxidant concentration

Composition comprising a metal oxide and a metal oxide	Time, hour	PAA,ppm	H₂O₂,ppm	Log₁₀Residual amount of	Log₁₀Reduction of
						Control	4	n/a	n/a	9.2	N/A
PAA	1	63	35	7.8	1.4
						PAA	2	54	27	7.0	2.2
PAA	4	30	10	6.1	3.1
						Composition 1	1	68	29	7.7	1.5
Composition 1	2	66	28	5.7	3.5
						Composition 1	4	58	18	0.0	Total kill
Composition 2	1	67	45	7.4	1.8
						Composition 2	2	63	35	5.2	4.0
Composition 2	4	59	28	0.0	Total kill

As shown in table 9, both equilibrium PAA solutions in micellar systems have higher biocide activity than peracetic acid alone at the same concentration. Compositions 1 and 2 also provided oxidizing agents (PAA and H) in the four hour post-treatment solution compared to peracetic acid alone₂O₂) Enhanced stability of.

Example 10

We further evaluated the biocidal activity of PAA-surfactant solutions on microbial biofilms using CDC biofilm reactors from BioSurface Technologies, as described in example 9. The three biocide solutions were also as described in example 9, but the contact time was increased to about 72 hours with stirring. In addition, for this test, aliquots of biocide were increased from 4mL to 30mL of the standard method. These adjustments are made to more accurately simulate expected field conditions. Recovery was performed as described in example 8. Tests showed that all three biocides were completely killed. Chemical analysis showed that the concentrations of PAA and hydrogen peroxide decreased only slightly within 72 hours.

In addition to microbial recovery, a visual inspection of the biofilm remaining on the glass coupons after biocide treatment was also performed. The test pieces were observed visually and by means of a Leica optical microscope. Images were captured with the apparatus of the card, and are shown in fig. 1 a-1 d.

Visual inspection showed that more biofilm was removed in the coupons treated with compositions 1 and 2 than those treated with PAA alone. The untreated control coupon was completely coated with biofilm.

Claims

1. A composition comprising a source of active oxygen, an organic acid, and a surfactant, wherein the organic acid and the source of active oxygen react to form an equilibrium peroxycarboxylic acid solution in a micellar system.

2. The composition of claim 1, wherein the active oxygen source is selected from the group consisting of: hydrogen peroxide, calcium peroxide, percarbonate, carbamide peroxide and mixtures thereof.

3. The composition of claim 2, wherein the active oxygen source is hydrogen peroxide.

4. The composition of claim 1, wherein the organic acid is selected from the group consisting of: acetic acid, formic acid, propionic acid, octanoic acid and citric acid.

5. The composition of claim 4, wherein the organic acid is acetic acid.

6. The composition of claim 1, wherein the surfactant is a nonionic surfactant.

7. The composition of claim 1, wherein the surfactant is an anionic surfactant.

8. The composition of claim 1, wherein the surfactant is biodegradable.

9. The composition of claim 1, wherein the surfactant is a linear alcohol or a derivative of a linear alcohol.

10. The composition of claim 9, wherein the linear alcohol is a C6-C12 linear alcohol.

11. The composition of claim 1, wherein the surfactant is an alcohol ethoxylate, an alkoxylated linear alcohol, an ethoxylated castor oil, an alkoxylated fatty acid, an alkoxylated coconut oil, an alcohol sulfate, a monoglyceride phosphate, a diglyceride phosphate, or a combination thereof.

12. The composition of claim 1, further comprising a stabilizer.

13. The composition of claim 12, wherein the stabilizer is a hydroxy acid.

14. The composition of claim 13, wherein the hydroxy acid is citric acid, malic acid, lactic acid, salicylic acid, or glycolic acid, or a combination thereof.

15. The composition of claim 1 wherein the equilibrium peroxycarboxylic acid solution has a concentration of about 10-15% by weight of the composition.

16. The composition of claim 1 wherein the equilibrium peroxycarboxylic acid solution comprises a peroxycarboxylic acid, an organic acid, and hydrogen peroxide.

17. The composition of claim 16, wherein the percarboxylic acid is a C2-C12 percarboxylic acid.

18. The composition of claim 17, wherein the percarboxylic acid is peracetic acid.

19. The composition of claim 1, wherein the micellar system comprises particles from about 2nm to about 900 nm.

20. The composition of claim 1 wherein the concentration of the equilibrium peroxycarboxylic acid solution is stable for at least about five months.

21. The composition of claim 20 wherein the equilibrium peroxycarboxylic acid solution retains about 80% of the initial equilibrium activity.

22. The composition of claim 20 wherein the equilibrium peroxycarboxylic acid solution retains about 75% of the initial equilibrium activity.

23. The composition of claim 1, wherein the composition is homogeneous.

24. The composition of claim 1, wherein the pH of the composition is from about 1.0 to about 4.0.

25. A micellar system comprising an equilibrium peroxycarboxylic acid solution and a surfactant.

26. The micellar system of claim 25, wherein the equilibrium peroxycarboxylic acid solution comprises a peroxycarboxylic acid, an organic acid, and hydrogen peroxide.

27. The micellar system according to claim 26, wherein the percarboxylic acid is peracetic acid.

28. The composition of claim 26, wherein the organic acid is acetic acid.

29. The micelle system according to claim 25 wherein the micelle comprises a non-ionic surfactant.

30. The micelle system according to claim 25 wherein the micelle comprises an anionic surfactant.

31. The micelle system of claim 25, wherein the micelle comprises a surfactant, wherein the surfactant is an alcohol ethoxylate, an alkoxylated linear alcohol, an ethoxylated castor oil, an alkoxylated fatty acid, an alkoxylated coconut oil, an alcohol sulfate, a monoglyceride phosphate, a diglyceride phosphate, or a combination thereof.

32. The micellar system according to claim 25, further comprising a stabilizer.

33. The micellar system of claim 32, wherein the stabilizer is a hydroxy acid.

34. The micellar system according to claim 33, wherein the hydroxy acid is citric acid, malic acid, lactic acid, salicylic acid or glycolic acid or a combination thereof.

35. A method of making a micellar system comprising an equilibrium peroxycarboxylic acid solution, the method comprising:

a) mixing about 30-50 wt% of an organic acid, about 10-20 wt% of a source of active oxygen, and about 1-15 wt% of a surfactant in an aqueous solution;

b) incubating the aqueous solution for a sufficient time to produce the equilibrium peroxycarboxylic acid solution.

36. The method of claim 35, wherein the organic acid, the active oxygen source, and the surfactant are mixed simultaneously.

37. The method of claim 35, wherein the organic acid, the active oxygen source, and the surfactant are mixed sequentially.

38. The method of claim 35, wherein the culturing step is from about 8 days to about 50 days.

39. A method of reducing microbial contamination in an aqueous fluid, the method comprising:

contacting the aqueous fluid with a composition comprising a micellar system comprising an equilibrium peroxycarboxylic acid solution and a surfactant for a sufficient time to reduce the level of microorganisms in the aqueous fluid.

40. The method of claim 39, wherein the aqueous fluid is fresh water, pond water, seawater, brackish water, or brine.

41. The method of claim 39, wherein the aqueous fluid is an oilfield fluid, produced water, tower water, or a combination thereof.

42. The method of claim 39 wherein the composition is added to the aqueous fluid to be treated in an amount sufficient to provide from about 10ppm to about 1000ppm of activated percarboxylic acid in the aqueous fluid.

43. The method of claim 39 wherein the composition comprising a micellar system is added to the aqueous fluid in an amount sufficient to provide from about 50ppm to about 8000ppm of the composition.

44. The process of claim 39, wherein the percarboxylic acid is peracetic acid.

45. A method of reducing microbial contamination in a subterranean environment comprising a wellbore, the method comprising:

a) introducing an aqueous composition comprising a micellar system comprising an equilibrium peroxycarboxylic acid solution and a surfactant into the wellbore;

b) contacting the well with the aqueous composition for a sufficient time to reduce microbial contamination.

46. The method of claim 45, wherein said microbial contamination comprises a free-floating microbial population.

47. The method of claim 45, wherein said microbial contamination comprises a sessile microbial population.

48. The method of claim 45, wherein said microbial contamination comprises a biofilm.

49. The method of claim 45 wherein the composition is added to an aqueous fluid in an amount sufficient to provide from about 10ppm to about 1000ppm of the activated percarboxylic acid.

50. The process of claim 45, wherein the percarboxylic acid is peracetic acid.

51. A method of reducing microbial contamination of a surface, the method comprising contacting the surface with an aqueous composition comprising a micellar system comprising an equilibrium peroxycarboxylic acid solution and a surfactant for a sufficient time to reduce microbial contamination.

52. The method of claim 51, wherein said microbial contamination comprises a biofilm.

53. The method of claim 51, wherein the surface is selected from industrial equipment, medical equipment, or equipment used in food preparation.